Grinding wheel and mounting assembly

ABSTRACT

A solid grinding wheel substantially in the form of a cloverleaf having equiangular spaced petals and the like spaced roots defined therebetween, the spaced roots receiving flanged retaining pins securing the grinding wheel to a rotatable drive shaft. The shanks of the flanged retaining pins include a portion of increased diameter including a tapered cam surface engaged by a like tapered cam surface on an adjustable nut of a chuck mounting assembly. The adjustable nut is internally threaded and received upon a sleeve in the chuck assembly and presents a tool receiving end through which the shanks of the retaining pins are received with the flanges engaging the outside surface of the grinding wheel. Tightening movement of the nut engages the mating tapered cam surfaces axially moving the retaining pins drawing the grinding wheel into engagement with an end of the driving shaft. A conical protuberance is provided on one surface of the grinding wheel and is received in a like recess in the end of the driving shaft thereby aligning the wheel on the shaft prior to firmly securing it by rotation of the adjustable nut. Coolant fluid passages are provided in the flanged retaining pins so that coolant fluid is directed onto work engaging surfaces of the grinding wheel beneath a wind barrier created when the wheel is rotated at high speeds. The adjustable nut can be formed to accommodate a fluid collector sleeve which is secured to the nut and extends away from the grinding wheel terminating in an arcuate portion receiving coolant discharged from a source under pressure, the fluid being received by the collector sleeve and directed through the passages in the flanged pins for discharge onto the grinding wheel work engaging surfaces.

United States Patent [191 Sipe ' GRINDING WHEEL AND MOUNTING ASSEMBLYTherell L. Sipe, Sandusky, Ohio [73] Assignee: General MotorsCorporation,

Detroit, Mich.

[22] Filed: Aug. 8, 1972 [21] Appl. No.: 278,768

[75] Inventor:

Peterson 51/168 X Herczeg 51/168 X Primary Examiner-Donald G. KellyAtt0rneyFrank J. Soucek et a1.

[57] ABSTRACT A solid grinding wheel substantially in the form of acloverleaf having equiangular spaced petals and the like spaced rootsdefined therebetween, the spaced roots receiving flanged retaining pinssecuring the grinding wheel to a rotatable drive shaft. The shanks Dec.25, 1973 of the flanged retaining pins include a portion of increaseddiameter including a tapered cam surface engaged by a like tapered camsurface on an adjustable nut of a chuck mounting assembly. Theadjustable nut is internally threaded and received upon a sleeve in thechuck assembly and presents a tool receiving end through which theshanks of the retaining pins are received with the flanges engaging theoutside surface of the grinding wheel. Tightening movement of the nutengages the mating tapered cam surfaces axially moving the retainingpins drawing the grinding wheel into engagement with an end of thedriving shaft. A conical protuberance is provided on one surface of thegrinding wheel and is received in a like recess in the end of thedriving shaft thereby aligning the wheel on the shaft prior to firmlysecuring it by rotation of the adjustable nut. Coolant fluid passagesare provided in the flanged retaining pins so that coolant fluid isdirected onto work engaging surfaces of the grinding wheel beneath awind barrier created when the wheel is rotated at high speeds. Theadjustable nut can be formed to accommodate a fluid collector sleevewhich is secured to the nut and extends away from the grinding wheelterminating in an arcuate portion receiving coolant discharged from asource under pressure, the fluid being received by the collector sleeveand directed through the passages in the flanged pins for discharge ontothe grinding wheel work engaging surfaces.

3 Claims, 3 Drawing Figures GRINDING WHEEL AND MOUNTING ASSEMBLY Thisinvention relates to a grinding wheel and mounting device thereforproviding a means for securing a solid grinding wheel for high speedoperation and more specifically to a solid grinding wheel, cloverleaf inform, having equiangular spaced petals and being retained by flangedpins having coolant fluid conducting passages therein.

In high speed operation, it is necessary to mount a grinding wheelcomposed of bonded abrasive particles in the most positive mannerpossible. An aperture through such a wheel for the purpose of receivinga fastening device necessarily results in a concentration of forces inthe wheel in the area of the aperture. This concentration of forcesfrequently results in undesirable fracturing of the wheel. Also duringhigh speed grinding operations it is desirable to supply a coolant fluidto the work engaging surfaces of the wheel so as to prevent generationof heat sufficient to create temperatures which may effect the bondingcharacteristics of the wheel. The supply of coolant fluid to the workengaging surfaces is difficult to accomplish because of a wind barrier,spaced from but conforming to the work engaging surfaces of the wheel,developing during high speed grinding operations.

In accordance with the disclosure of the present application, theseobjective are achieved in a structural combination of a chuck supportinga solid grinding wheel. The chuck is mounted on a drive shaft extendingthrough the chuck into engagement with a side surface of the grindingwheel. The side surface of the wheel has an axially extendingprotuberance that is received in a recess in the end of the drive shaftpositioning the wheel relative to the shaft. In preferred form, thesolid grinding wheel resembles a cloverleaf including petals with rootstherebetween. Pins having flanged or headed ends and containing coolantfluid conducting passages are disposed in the roots so that headed endsengage the exterior side surface of the solid grinding wheel. The shanksof the pins are received in the chuck adjacent the drive shaft. Anadjustable nut associated with the chuck assembly includes cam surfacesengaging like surfaces on the retaining pins so that rotation of the nutmoves the pins axially relative to the drive shaft. The engagement ofthe headed ends of the pins against the exterior side surface of thesolid grinding wheel consequently draws the wheel into firm engagementwith the end of the drive shaft providing a positive moutingarrangement.

A general object of this invention is to provide a solid grinding wheeland mounting means therefor capable of withstanding high speed grindingoperations.

A further object of this invention is the provision of a solid grindingwheel, cloverleaf in form, defining roots receiving headed retainingpins, the shanks of which are firmly secured in a chuck assembly.

Another object of the subject invention is the provision of a cloverleafform solid grinding wheel that is retained by flanged pins in a chuckmounting assembly, the retaining pins including an enlarged diametricalshank portion having a tapered surface thereon which is engaged by alike surface on the adjusting nut of the chuck assembly so that the pinsare axially moved when the nut is rotated securely fastening the wheelagainst a driving shaft.

A still further object of the subject invention is the provision ofcoolant passages in the headed retaining pins for transmitting coolantfluid to the work engaging surfaces of a solid grinding wheel beneath awind barrier created during high speed operation.

Another object of the subject invention is to provide coolant passagesin headed retaining pins directing coolant fluid to work engagingsurfaces of a solid grinding wheel and to secure a fluid collectorsleeve to a chuck assembly securing the headed retaining pins so thatthe collector sleeve receives fluid from a pressurized source anddirects it through the passages in the headed retaining pins.

The novel features which I believe to be characteristic of my inventionare set forth with particularlity in the appended claims. My inventionitself, however, both as to its organization and method of operation maybe best understood by referring to the following description taken inconjunction with the accompanying drawing in which:

FIG. 1 is a side elevational view with portions broken away illustratingthe grinding wheel and mounting assembly of the subject invention.

FIG. 2 is an end view taken in the direction of lines 22 in FIG. 1.

FIG. 3 is an exploded isometric view illustrating the specific elementsof the grinding wheeland mounting assembly of the subject invention.

Referring now to the drawing, in FIG. 1 a solid grinding wheel of thesubject invention is shown mounted against end 12 of a drive shaft 14. Aplurality of headed pins 16 are received within a chuck assembly 18 toretain the wheel 10 against drive shaft end 12. The pins 16 include aflanged head 20 which engages an exterior side surface 22 of thegrinding wheel 10 as shown. The pins 16 also have a shank portion 24which is enlarged in diameter relative to shank portions 26 and 28 ofthe pin and includes a tapered cam surface 30. The pins 16 terminate ina second enlarged shank portion 32 for a purpose later described.

The chuck assembly 18 is secured to drive shaft 14 in a conventionalmanner not shown. It includes an externally threaded sleeve 34 which ispositioned relative to a slightly enlarged section 36 of the drive shaft14 so that the internal surface 38 of the sleeve 34 and the externalsurface 40 of the drive shaft cooperate to define an aperture guidingaxial movement of the pin 16 therebetween as the enlarged shank portion32 engages both surfaces. The aforementioned enlarged shank portion 24includes a circumferential surface 42 engaging a slightly reduceddiameterical surface 44 of the drive shaft 14 to also guide axialmovement of the pin 16 within the chuck assembly 18. The chuck assembly18 further includes an adjustable nut 46 which is threadably receivedupon sleeve 34 and is formed to include a tapered cam surface 48matingly engaging like surface 30 of pin 16. The adjustable nut 46 canbe provided with a relieved portion 49 fixedly mounting a fluidcollector sleeve 50 which in turn includes a rearwardly and inwardlyextending arcuate portion 52 which receives coolant fluid from a sourceunder pressure such as shown at a nozzle 54 for purposes of illustrationonly.

As more specifically shown in FIGS. 2 and 3, the solid grinding wheel 10is cloverleaf in form including petals 56 with roots 58 therebetween.The grinding wheel 10 further includes, in preferred form, a conicalprotuberance 60 which extends from side surface 62 rearwardly forengagement with a mating aperture 64 formed in the end 12 of drive shaft14. These figures clearly illustrate that the flanged heads of pins 16are received within the roots 58 of the solid grinding wheel so that theflanges engage the external side surface 22 of the grinding wheel.

In operation, the solid grinding wheel 10 with its protuberance 60positioned within aperture 64 of the drive shaft 14 is centrally alignedon the end 12 of the drive shaft. The pins 16, with their headed flanges20 engaging side surface 22 of the grinding wheel, are received withinthe chuck assembly 18 when the adjustable nut 46 has been sufficientlyrotated to expand the chuck assembly. As this time the enlarged shankportion 24 with its tapered cam surface 30 is positioned adjacent themating cam surface 48 of the adjustable nut 46. Likewise, the enlargedshank portion 32 of the pins 16 are received between the interiorsurface 38 of sleeve 34 and the exterior surface 40 of the enlargedportion 36 of shaft 14. Also the circumferential surface 42 of theenlarged shank portion 24 engages exterior surface 44 of the drive shaft14 so that the pins are positively positioned but yet loosely retainedwithin the chuck assembly 18 for axial movement therein when the nut 46is rotated in a tightening direction. Tightening movement of the nut 46engages cam surface 48 with cam surface 30 of the pins 16 slidablymoving the engaging surfaces of the enlarged shank portions alongexterior surfaces 40 and 44 of the drive shaft 14 as well as alonginterior surface 38 of sleeve 34. The guiding axial movement of the pinscontinues until the headed flanges 20 are drawn tightly against sidesurface 32 of the grinding wheel 10 so that the interior surface 62 ofthe wheel is in rigid contact with end surface 12 of drive shaft 14thereby positively retaining the wheel 10 upon the end 12 of shaft 14for use during high speed grinding operations.

Ifit is desired to supply a coolant fluid to work engaging surfaces 11of the solid grinding wheel 10, the fluid is supplied through nozzle 54adjacent the arcuate portion 52 of collector sleeve 50. The arcuateportion 52 catches the coolant fluid and supplies it to passages 27 inthe pins 16 from which it exits laterally extending passages 17 fordistribution about the periphery about the grinding wheel 10 and morespecifically to the work engaging surfaces 11. The supplying of thecoolant fluid through pin passages 27 and the lateral passages 17results in the fluid being discharged beneath a wind barrier thatdevelops around the wheel during high speed operation. Obviously thesupplying of the fluid in this manner eliminates the problem ofattempting to pass the coolant fluid through the wind barrier duringrotation of the grinding wheel 10.

While I have shown and described a specific embodiment of the presentinvention it will, of course, be understood that various modificationsand alternative constructions may be made without departing from itstrue spirit and scope. In particular, it is possible to vary thespecific configuration of the cloverleaf form of the solid grindingwheel 10 so as to present a work engaging surface 11 of different formthan that illustrated in FIGS. 2 and 3. Further, it is possible to varythe configuration of collector sleeve 50 which is provided to collectthe coolant fluid and supply it to the passages 27 in the retaining pins16. With these possibilities in mind, therefore, I intend by theappended claims to cover all modifications of the subject inventionwhich fall within their true spirit and scope.

I claim:

1. In a solid grinding wheel and chuck assembly secured to a driveshaft, a sleeve defining a tool receiving opening and including anadjustable nut threadably mounted on the sleeve, the nut having atapered cam surface on the inner periphery thereof adjacent an axialopening registering with the opening in said sleeve, comprising incombination; a grinding wheel proper defined by a generally cloverleafdisk-like body of grinding material having equiangular spaced petalsdefining roots therebetween in axial alignment with the tool receivingopening in said sleeve, said drive shaft having a grinding wheelaligning cavity in an end surface, a centering protuberance on saidsolid grinding wheel received in the shaft aligning cavity, a pin havinga flanged headed end received in each of the roots and in the toolreceiving cavity of said chuck sleeve as well as within the axialopening in said adjustable nut, and a tapered cam surface on said headedpin engaged by said tapered cam surface on said adjustable nut so thattightening movement of said nut axially moves said pins engaging theirheads with a side surface of said grinding wheel adjacent said rootsdrawing the wheel tightly against the end of said shaft for high speedrotation.

2. In a solid grinding wheel and chuck mounting assembly adapted to besecured to a drive shaft, a sleeve in said chuck defining a toolreceiving opening and an adjustable nut coaxially threadably mounted onsaid sleeve and having an axial opening in alignment with the opening insaid sleeve, the adjustable nut also having a tapered cam surfaceadjacent the axial opening, the combination comprising; a grinding wheelproper defined by a generally cloverleaf disk-like body of grindingmaterial having spaced petals and roots therebetween, the roots being inaxial alignment with the tool receiving cavity in said sleeve, saiddrive shaft extending through said chuck assembly and having an endsurface with a grinding wheel aligning cavity therein, a centeringprotuberance on a side surface of said grinding wheel received in saidshaft aligning cavity, a retaining pin having a headed end and a shankportion, the headed end of a pin each being positioned in a respectiveroot of the grinding wheel while the shank portions are received withinthe aligned openings in said chuck, an enlarged portion on said shankengaging the exterior surface of said drive shaft, a tapered cam surfaceon said enlarged chuck portion adjacent said cam surface on saidadjustable nut, rotation of said adjustable nut in a tighteningdirection axially moving said pins by the engagement of the said nut andsaid pin shank portion cam surfaces drawing their heads against a sidesurface of said solid grinding wheel adjacent each root therein andfurther tightening movement of said adjustable nut tightly engaging aside surface of said grinding wheel with the end surface of said driveshaft for high speed rotation thereof, said pins each containing anaxial passage connecting with a lateral discharge passage adjacent theperipheral edge of said solid grinding wheel, and a collector sleevesecured to said chuck assembly and configured to receive and collectcoolant fluid supplied under pressure from an external source fordirection through the axial passages and discharge onto the peripheralsurface and consequently the work engaging surfaces of said solidgrinding wheel.

3. The combination as described in claim 2 wherein said headed retainingpins further comprise a second enlarged shank portion adjacent theirends opposite from said heads, the enlarged portion being receivedbetween the exterior surface of said drive shaft and an internal surfaceof said chuck sleeve for guiding said pins during their axial movementin a grinding wheel tightening direction.

1. In a solid grinding wheel and chuck assembly secured to a driveshaft, a sleeve defining a tool receiving opening and including anadjustable nut threadably mounted on the sleeve, the nut having atapered cam surface on the inner periphery thereof adjacent an axialopening registering with the opening in said sleeve, comprising incombination; a grinding wheel proper defined by a generally cloverleafdisk-like body of grinding material having equiangular spaced petalsdefining roots therebetween in axial alignment with the tool receivingopening in said sleeve, said drive shaft having a grinding wheelaligning cavity in an end surface, a centering protuberance on saidsolid grinding wheel received in the shaft aligning cavity, a pin havinga flanged headed end received in each of the roots and in the toolreceiving cavity of said chuck sleeve as well as within the axialopening in said adjustable nut, and a tapered cam surface on said headedpin engaged by said tapered cam surface on said adjustable nut so thattightening movement of said nut axially moves said pins engaging theirheads with a side surface of said grinding wheel adjacent said rootsdrawing the wheel tightly against the end of said shaft for high speedrotation.
 2. In a solid grinding wheel and chuck mounting assemblyadapted to be secured to a drive shaft, a sleeve in said chuck defininga tool receiving opening and an adjustable nut coaxially threadablymounted on said sleeve and having an axial opening in alignment with theopening in said sleeve, the adjustable nut also having a tapered camsurface adjacent the axial opening, the combination comprising; agrinding wheel proper defined by a generally cloverleaf disk-like bodyof grinding material having spaced petals and roots therebetween, theroots being in axial alignment with the tool receiving cavity in saidsleeve, said drive shaft extending through said chuck assembly andhaving an end surface with a grinding wheel aligning cavity therein, acentering protuberance on a side surface of said grinding wheel receivedin said shaft aligning cavity, a retaining pin having a headed end and ashank portion, the headed end of a pin each being positioned in arespective root of the grinding wheel while the shank portions arereceived within the aligned openings in said chuck, an enlarged portionon said shank engaging the exterior surface of said drive shaft, atapered cam surface on said enlarged chuck portion adjacent said camsurface on said adjustable nut, rotation of said adjustable nut in atightening direction axially moving said pins by the engagement of thesaid nut and said pin shank portion cam surfaces drawing their headsagainst a side surface of said solid grinding wheel adjacent each roottherein and further tightening movement of said adjustable nut tightlyengaging a side surface of said grinding wheel with the end surface ofsaid drive shaft for high speed rotation thereof, said pins eachcontaining an axial passage connecting with a lateral discharge passageadjacent the peripheral edge of said solid grinding wheel, and acollector sleeve secured to said chuck assembly and configured toreceive and collect coolant fluid supplied under pressure from anexternal source for direction through the axial passaGes and dischargeonto the peripheral surface and consequently the work engaging surfacesof said solid grinding wheel.
 3. The combination as described in claim 2wherein said headed retaining pins further comprise a second enlargedshank portion adjacent their ends opposite from said heads, the enlargedportion being received between the exterior surface of said drive shaftand an internal surface of said chuck sleeve for guiding said pinsduring their axial movement in a grinding wheel tightening direction.